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The Scraper A sharp burr makes shavings, not dust

by Stephen Proctor

T

he term scraper brings to mind a tool for cleaning blis-

tered paint from the sides of a house, or for chipping rust

from the deck of a ship. It seems a poor term for such a

fine tool, a tool capable of the finest of cuts and the heights of

accuracy, an almost indispensable tool around a furniture shop.

The term is something of a misnomer, for when sharpened to a

burr edge, a scraper cuts rather than scrapes, much like a very low angle plane blade or chisel, slicing off paper-thin shavings

of wood. As useful as the scraper is, it's surprising how few peo-

ple understand how to sharpen and how to use it.

Scrapers come in various sizes and thicknesses and the meth-

ods I will describe for sharpening and use are the same for all.

A st an da rd scrap er , goo d for most wor k, is a in . by 5- in .

piece of steel, about in. thick. Scraper hardness varies; I have

had little luck using my methods on scrapers advertised as hav-

ing hardened edges. For curved surfaces, a thin flexible steel

that will conform to the curve is better. A gooseneck scraper

(the whale-shaped one in the photo at right) contains a variety

of curves that can be used on tight curves or moldings. I have

four or five scrapers around so I don't have to stop and sharpenso frequently,

A rectan gul ar scraper con sists of fou r narro w edg es and two

broad faces. The cutting is done by a small burr formed at the

juncture of a face and an edge (such a juncture is called an arris,

as indicated in the drawing on the next page). The quality of the

burr, and of the cut it makes, is entirely dependent on the quality

of the intersecting surfaces. Two smooth, blemish-free surfaces

produce a stronger burr with fewer of the microscopic serrations

that produce a rough surface on the wood.

To sharpen the scraper, first dress the two long edges with a

single-cut mill file. Clamp the scraper vertically in a vise and

draw the file along the edge, trying to achieve a straight edge,

perfectly square in cross section. All four arrises should feel

sharp to the touch, if not, refile until they do.Next, polish the faces of the scraper with a medium India

stone followed by a fine, hard finishing stone—I use a hard black

Arkansa s ston e. Be car efu l to keep the scraper fl at on the ston es,

or you'll round the arris. Then, holding the scraper vertically be-

tween both hands, polish each long edge, rubbing the scraper to

and fro along each stone in turn. Hold it diagonally across the

stone to prevent uneven wear to the stone. Don't be tempted to

polish on the edge of the stone, using the box holding the stone

as a 90° guide—repeated polishings will wear a groove in the

stone and round the edge of the scraper. After this operation, all

four edges should again feel sharp to the touch.

A bu rni sh er is requ ir ed for the next step . It mu st be smo oth

A scraper, most often nothing more than a piece of thin steel,can be any of a variety of shapes. Common commercial scrapers are rectangular and gooseneck, shown in the center above.

After filing, work the faces and edges of the scr aper on a med i-um and a hard stone. Hold the scraper diagonally across the stone's width to prevent wearing the stone unevenly.

P h o t o s : C h a r l e s S w a n s o n

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To raise the burr, hold the burnisher at a slight angle to the face and stroke it firmly back and forth along the arris. To turn the burr, make a single firm pass along the arris, the bu rnisher held slightly less than perpendicular to the face.

To scrape a flat surface(right), hold the scraper as nearly perpendicular to the work as possible and push or

pull i t to take wide shavings. A gooseneck scraper is ideal for tight curv es (top). A flexed rec-tangular scraper can scrape shallow concave and convex surfaces (bottom).

and of a harder steel than the scraper. If it isn't smooth, it willabrade the scraper and damage the burr. You can buy burnishers,

but many things will work as well. My preference used to be the

back of an old gouge. Currently I use a buffed-up pushrod from

an automobile engine. Whatever you use, it may help to apply alittle lubricant between burnisher and scraper. Oil is fine, or just

rub the burnisher across your nose—it really does work.

Two steps are required to make a burr: raising the burr and

turning it. To raise the burr, lay the scraper flat on the edge of a

firm surface, hold the burnisher almost in the same plane (a few

degrees off horizontal) and stroke it firmly back and forth alongeach arris. You should hear a loud tick as the burnisher goes off

the end of the scraper at the end of each stroke. Hence the term

ticketer, as the burnisher was once known. The resulting crosssection is shown in the drawing and can easily be seen on thescraper with the aid of a magnifying glass.

There are many methods of turning the burr—the following

one works well for me and is quicker than others I have tried.Holding the scraper vertically in the left hand, stick one of its

corners into the bench, push it firmly into the surface to create a

slight curve in the steel. Then, starting the burnisher near the top

corner of the scraper and holding it at a fraction less than 90° to

the face of the scraper, take one firm stroke down the arris, as

shown above. Finish the small unburnished section at the top wit h a sho rt upward st roke . Rep eat thi s process on the other

three arrises, making sure to turn the burr on the concave arris

each time. It isn't necessary to curve the scraper to turn a burr,

but I think that it puts a little tension in the burr once the curve

is released, and this makes the burr a little stronger.

Taking several passes will turn a large burr, which will take a

large shaving. However, a large burr takes longer to turn than asmall one, and I've found them to be more brittle, possibly be-

cause of rnetal fatigue caused by the repeated passes made when

turning the burr. In addition, a large burr has relatively little sub-stance behind it to dissipate the heat generated during a cut, and

this also tends to make it degrade rapidly. I prefer a small burr

because it's less work in the long run. Gooseneck scrapers aresharpened by the same method, though the curves make the job

a little more difficult.

Scrapers are most commonly used to remove a fa i r amount of wood from a flat surface. Why scrape, rather than plane or sand?

A plane may tear interlocking or curly grain, but the scraper can

manage nearly any awkward grain. The scraper face immediately behind the burr acts like a very finely set chip breaker, fracturing

the severed wood fibers before they can tear out. A scraper also

removes material quickly and leaves a finished surface, unlike

coarse- or medium-grit abrasive paper, which removes the same

amount of material, but leaves scratches.

To maintain the flatness of a large surface, like a tabletop, it is

essential to cover as large an area as possible with one stroke of

the scraper and to introduce as little curvature to the cutting

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edge as possible. A curved scraper will make a concave cut—the

greater the curvature, the greater the concavity. To avoid curva-

ture, hold the scraper with your fingers behind the cutting edge

and thumbs in front. Maintain a constant angle to the wood, as

close to perpendicular as possible, and draw the scraper toward

you , att em pt in g to prod uce a sha ving almo st the fu ll width of the

scraper. Proceed across the surface with a series of long and

slightly overlapping strokes. I prefer to pull the scraper, but you

can push it, too, as shown above. It's easier to curve the tool

wh en pu sh in g, so be ca re fu l.

Unlike a plane, the scraper has no sole and may, therefore,

ride up and down over hard and soft areas and create ridges onthe surface. To avoid this, the scraper should be slightly diagonal

to the direction of the wood grain. Alternate the diagonal orien-tation every other stroke, so that the edge will only take material

from the high spots, leaving a flat surface.

For a fine, finishing cut, a small, sharp burr is needed; if the

scraped surface isn't good enough, re-stone the scraper and turnanother burr. Hold and move the scraper as described previous-

ly, keeping it as perpendicular to the surface as possible. Obsti-

nate grain may require that the angles diagonal to the grain be

increased to produce a skewed cut.

The third basic scraper technique is for shaping or truing con-

cave or convex surfaces. Depending on the curves, use a flexible

rectangular scraper or a gooseneck scraper, as shown on the fac-ing page. By springing the scraper between fingers and thumb,

the cutting edge can be made to conform to a variety of curves.

As the curve of the scraper tightens, the cutting angle of the

scraper is inevitably lowered. As the scraper is lowered, the bur-

nishing angle of the burr must also become more acute to main-

tain the proper cutting angle of the burr to the wood. You may

need to experiment with various angles at first, but you'll get the

feel of it with experience.

The most common fault when using a scraper is to concentrate

all your energy on one small flaw—a slight tear or, most fre-

quently, an edge joint in a veneered surface. The resulting sur-

face looks as though it has been bombarded by billiard balls or

has had a drainage ditch cut down it. To avoid this natural attrac-tion to flaws, a good rule of thumb is to take two strokes either

side of the flaw for every stroke on it. Also, try to cover as muchground as possible with each stroke.

As soon as the scraper no longer takes a shaving, it's time to

resharpen. It is possible to re-turn a burr with the burnisher sever-

al times before having to go back to the file and the stones. Bur-nish the face first, then turn the burr at the desired angle. Whenthe burr is ragged and leaves striations in the wood's surface, it's

time to go back to the beginning of the process. Putting off sharp-

ening because of laziness costs time and energy. The joy of using

a sharp scraper is well worth the effort that it takes.

Stephen Proctor, a woodworker for 34 years, is Dean of Instruc-tion for the Wendell Castle School.

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